Regression Analysis of Automatic Measurement Systems

In this paper, regression analysis is presented to analyze the comparative performance capability between two functionally equivalent but technologically different automatic measurement systems for acceptance testing of a unit under test (UUT). Since the pass/fail criteria of a UUT are contingent upon repeatable and reproducible accurate measurements, a methodology is presented to examine if there is a statistically significant difference between two functionally equivalent automatic measurement systems. The purpose of which is to reduce the technical risk of transportability issues that occur when a UUT is in transition from the legacy measurement system to an emerging measurement system.     

基于PSASP的自动电压调节器对电力系统稳定性物理分析

电压、频率、畸变率和供电可靠性都是衡量电能质量的标准。基于PSASP对自动电压调节器AVR的参数进行改变,观察其对于系统稳定性的影响。     

低压岸电系统及其效益分析

岸电系统对于电厂尤其是下水煤电厂的环保工作具有重要意义。在保证安全环保可靠的基础上，提出了一种适合电厂码头实际运行需要的系统结构；与传统的岸电相比，提出了变频及并网的概念，并可同时兼容400 V/50 Hz、440 V/60 Hz这2种制式的船舶靠港对接。分析了电缆收放系统以及并网存在的主要问题，最后对成本及收益进行了分析，指出这样的结构会使系统的成本大大降低，同时利用电厂在电价方面的优势，低压岸电系统可以在下水煤电厂得到大规模的推广应用。     

Automatic Digital Correction of Errors of Microprocessor Systems for Metering Electrical Power

A universal digital method for automatically correcting errors of analog-to-digital converters is considered which forms the basic functional element of a microprocessor system for metering electrical power. The essence of the operation of an algorithm for automatically correcting errors utilizing the method of standard signals is indicated.     

高压电力电缆故障分析及其探测技术

针对高压电缆运行中各种类型故障,介绍电缆故障现场测试方法和测试经验.     

ZigBee技术在航空电源车自动检测上的应用

介绍了ZigBee技术的概念、特点,并给出了基于ZigBee技术的航空电源车自动检测与控制系统.通过对ZigBee技术在航空电源车自动检测上的应用进行分析,提出了该系统的硬件与软件设计,实现了数据的采集和无线传输.ZigBee技术在航空电源车自动检测上的应用,即利用ZigBee无线传感器对航空电源车数据进行采集,然后以ZigBee无线传输模式将这些数据传送到保障指挥中心,计算机对这些数据进行分析整理后,为保障指挥人员准确判断航空电源车状态提供依据,因此能够及时发现航空电源车的故障,减少了装备维修所需的时间,大大提高了装备保障的效率.     

自动包装机同步控制系统分析

对一种常见的引进生产线上的进口包装机的控制系统进行分析，同时对这类控制系统的设计，调试提供理论依据。     

高压电力计量系统CT二次侧故障检测方法

本文针对高压电能计量系统CT二次侧故障情况进行了分析,讨论了各种故障对计量造成的影响.在分析二次电流回路故障的基础上,提出了根据两个向量的相位关系判断故障的检测方法,该方法电路简单,测量参数少,易于判断.     

Analysis of Harmonics in Power Systems Using the Wavelet-Packet Transform

This paper proposes a new algorithm based on the wavelet-packet transform for the analysis of harmonics in power systems. The proposed algorithm decomposes the voltage/current waveforms into the uniform frequency bands corresponding to the odd-harmonic components of the signal and uses a method to reduce the spectral leakage due to the imperfect frequency response of the used wavelet filter bank. This paper studies the selection of the mother wavelet, the sampling frequency, and the frequency characteristics of the wavelet filter bank for the two most common wavelet functions used for harmonic analysis and compares the performance of the proposed method with the results obtained using the discrete Fourier transform (DFT) analysis and the harmonic-group concept introduced by the International Electrotechnical Commission (IEC) under different measurement conditions.     

全自动印品质量检测系统的技术分析

介绍了印品质量在线检测系统的结构、原理及意义,分析了该系统中图像采集、图像处理、模板建立等关键技术,介绍了图像采集及处理的方法,对模板的建立提出了取现法、特定样张法、比较平均法等多个解决方案,并对系统的应用进行了讨论,当系统的检测速度及精度达到一定要求后,可直接应用到印刷设备上,进行在线检测,使机器对墨量进行自行控制.     

Comparison of Nonactive Powers for the Detection of Dominant Harmonic Sources in Power Systems

This paper deals with an innovative technique for the detection of disturbing loads in distorted power systems. The technique is a single-point strategy based on a comparison among different “nonactive” power quantities already proposed in the literature, which are measured at the same metering section. In this paper, the effectiveness of the strategy is discussed, which also considered the errors of the measurement transducers; the analysis is supported by simulation tests, which were carried out on both a simple single-phase system and an IEEE standard three-phase test power system. The latter was used by other authors as a benchmark system for the analysis of multipoint measurement techniques for harmonic pollution monitoring.      

高频电压表自动检定系统

本文介绍了高频电压表自动检定系统 ,该系统应用计算机控制技术 ,根据热电变换原理和交直流替代方法 ,建立稳定、可靠、准确的电压标准量值 ,实现对高频电压表的自动检定、数据处理和证书打印     

燃油加油机快速自动检测装置测量不确定度分析

燃油加油机计量检定主标准器采用容积比较法进行,然后对测得的容积值进行温度补偿,以求得加油机的准确容积值.当选用磁致伸缩液位和热电阻传感器测量容积和温度值,对传统装置进行了自动化、小型化设计后,其整体测量不确定度如何?能否满足燃油加油机检定的装置技术要求?本文对整套装置的不确定度进行了分析.     

印刷自动套准偏差检测软件的主要技术问题分析

套准偏差检测软件是通过对实际印刷套准标记图像进行分析,获得自动套准偏差值,为后续的自动套准控制提供依据.主要讨论了套准偏差检测软件设计中需要解决的主要技术问题.其中包括:象素点的获取方法、象素点大小的设置、套准标记线端点坐标的确定、四色套准标记线叠印点的处理、不同背景色套准标记线的识别等.     

高压电力计量系统CT短路故障分析与检测

本文给出了电流互感器一次、二次侧短路以及二次相间短路故障的检测方法。首先通过对不同负荷下计量系统电路参数的分析,得出网络阻抗与电流互感器一次、二次侧短路之间的密切关系。其次,设计辅助电路,用于检测阻抗的变化,从而导出故障检测模型。最后,由于该模型不能检测电流互感器二次相间短路故障,因此又给出了该故障的检测方法。     

Microwave Two-Port Coaxial Power and Voltage Mounts

Two-port coaxial mounts to measure power, voltage, and current from audio to 36 GHz are described. These mounts need no RF calibration (thus eliminating accuracy degradation in the calibration hierarchy) and remove serious difficulties in measurements and equipment evaluation.     

Design of Automatic Guided Vehicle Systems

Designing an automatic guided vehicle system is a complex task. Besides hardware considerations, the design engineer should assess the impacts on facilities layout, material procurement policy, and production policy. In this paper we present some analysis techniques and a methodological framework for specifying the operational characteristics of an automatic guided vehicle system.     

A Time-Domain Approach for the Analysis of Nonstationary Signals in Power Systems

Voltage and current waveforms produced by several power systems are often characterized by a wide spectrum that contains numerous components, namely the fundamental, harmonics, and interharmonics. They can be properly analyzed through discrete Fourier transform (DFT)-based methods only if they remain stationary in time; in fact, in the presence of nonstationary components, DFT-based approaches do not grant reliable results because of the absence of a well-defined periodicity interval. The digital signal processing method proposed in this paper aims at analyzing a large category of nonstationary signals observed in power systems. It is capable of analyzing waveforms produced by power systems that seemingly operate in steady-state conditions, in which time-varying components represent anomalies, as well as waveforms generated by some power apparatuses, which supply nonstationary waveforms by design. The wide range of applicability of the proposed method is granted by a suitable processing scheme, including distributed filtering and phase unwrapping operations. Distributed filtering operations are performed to distinguish and separately analyze the major components contained in complex waveforms. Phase unwrapping operations are needed in the presence of nonstationary components characterized by heavy drifts and/or large swings in frequency.